Fuel injector for achieving smokeless combustion reactions at high pressure ratios

Abstract

High flame stability and good starting qualities are obtained in a relatively smoke free hot gas generator including a housing 10 having an interior combustion chamber 12 with a diverging interior wall 20 that is generally a surface of revolution. An axially directed opening 18 is centered in the wall 20 and an outer, oxidant inlet 48, 52 is provided and includes swirler vanes 50 for introducing into the chamber 12 at the interior wall 20 a swirling, hollow body of oxidant such that centrifugal force will create a diverging hollow body of swirling oxidant on the interior wall 20. A central fuel inlet 52, 58 is located within the opening 18 and within the oxidant inlet 48, 52 and is generally concentric therewith. The fuel inlet 52, 58 includes swirler vanes 50 for introducing a hollow cone-like body 90, 92 of atomized fuel into the chamber 12 such that the outer surface 94 of the cone-like body 90, 92 is on the inner surface 96 of the diverging body of oxidant from substantially the point of initiation of the latter to minimize mixing between the bodies.

I claim: 
     
       1. A hot gas generator comprising: a housing including an interior combustion chamber having a diverging interior wall that is generally a surface of revolution;   an axially directed opening centered in said wall;   an outer, oxidant inlet in said opening and including swirler vanes for introducing into said chamber at said interior wall a swirling, hollow body of oxidant such that centrifugal force will create a diverging hollow body of swirling oxidant on said interior wall; and   a central liquid fuel inlet within said opening and said oxidant inlet and generally concentric therewith, said fuel inlet including means comprising swirler vanes for introducing a swirling hollow cone-like body of atomized liquid fuel into said chamber such that the outer surface of said cone-like body is on the inner surface of said diverging body from substantially the point of initiation of the latter to minimize mixing between said bodies.   
     
     
       2. The hot gas generator of claim 1 wherein said swirler means comprising vanes are for causing said bodies to swirl in the same direction for minimum flame length and smoke. 
     
     
       3. The hot gas generator of claim 1 wherein said swirler means comprising vanes are for causing said bodies to swirl in opposite directions for maximum stability and flame starting. 
     
     
       4. The hot gas generator of claim 1 wherein said fuel inlet includes a nozzle with an axially facing discharge opening. 
     
     
       5. The hot gas generator of claim 4 wherein said nozzle includes a generally cylindrical outer surface defining part of said oxidant inlet and said discharge opening, in the direction of fuel flow, includes a first converging section merging with a second diverging section, said diverging section merging with said outer surface generally at said point of initiation. 
     
     
       6. The hot gas generator of claim 4 wherein said nozzle includes an outer surface defining part of said oxidant inlet and, in the direction of fuel flow, terminates in a converging outer surface, said discharge opening being defined by a converging inner surface, said opening further including a necked down area defining part of said oxidant inlet and aligned with said converging surfaces to delineate said point of initiation. 
     
     
       7. The hot gas generator of claim 1 further including fuel delivering means connected to said fuel inlet for delivering fuel thereto at a pressure sufficiently high that said combustor will operate at a pressure ratio in excess of 10/1.